Method and apparatus for detecting and measuring for Home Node-Bs

ABSTRACT

Methods and apparatus are disclosed for a wireless transmit/receive unit (WTRU) to detect and perform measurements with respect to Home Node-Bs (HNB) and Home evolved Node-Bs (H(e)NB) (collectively “HNB”). The methods may include generating and transmitting a request for a measurement configuration that may include gap allocations to detect and measure a primary scrambling code or a physical cell identity of a target HNB for at least one frequency or radio access technology (RAT). The request may be in response to the WTRU entering a HNB cell for which the WTRU has stored fingerprint information and whose closed subscriber group ID is in the WTRU&#39;s whitelist. The network may configure the WTRU to measure the requested frequency or RAT in response to the proximity report/request. Methods are described for releasing the measurement configuration.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. provisional application No.61/218,824 filed Jun. 19, 2009; U.S. provisional application No.61/248,003 filed Oct. 2, 2009; U.S. provisional application No.61/247,968 filed Oct. 2, 2009; and U.S. provisional application No.61/250,255 filed Oct. 9, 2009 and, which are incorporated by referenceas if fully set forth herein.

FIELD OF INVENTION

This application is related to wireless communications.

BACKGROUND

Home Node-Bs (HNBs) for Universal Mobile Telecommunications System(UMTS) and Home e-Node-Bs (HeNBs) for Long Term Evolution (LTE)(collectively, “Home Node-Bs” (HNBs)), have been introduced in Release 8of the 3rd Generation Partnership Project (3GPP) standard, for example,to increase cellular coverage and overall system throughput. HNBs arephysical devices (e.g., similar to wireless local area network (WLAN)access points (APs)) that provide access to UMTS and/or LTE servicesover extremely small service areas (or cells), such as private homes,small offices and coffee shops. As opposed to WLAN APs, which aregenerally accessible by wireless devices within their ranges, access toHNBs may be limited to smaller, more select groups of users referred toas closed subscriber groups (CSGs). Similar to WLAN APs, however, HNBsconnect their users' wireless devices to the HNB operator's corenetwork. For HNBs, the connection may be established using, for example,an internet connection (e.g., a digital subscriber line (DSL)). By wayof example, a coffee shop owner (or subscriber) may choose to deploy anHNB in his or her shop to provide patrons (the CSG in this example) witha stronger wireless connection than may otherwise be available insidethe shop. Due to their use in small service areas, HNBs may be denselydeployed and, accordingly, located within the coverage area of one ormore macro Node-Bs.

To enable certain functionalities for wireless devices or wirelesstransmit/receive units (WTRUs), such as handover (HO) between networknodes, it may be necessary for the WTRU to perform measurements, forexample, on other frequencies or systems. To perform these measurements,the WTRU may require gaps.

Inter-frequency measurement reporting rules do not cover scenarios whereit may be preferable for the WTRU to handover from a macro cellfrequency to an HNB frequency, even if the quality of the macro cellfrequency is still acceptable. The network typically configures the WTRUfor compressed mode with gaps to measure other frequencies when the WTRUis at the border of one or more cells and needs to handover to anotherfrequency.

The inter-frequency measurement reporting rules rarely apply to HNBs,which may be, for example, deployed in private homes localized anywherein the macro cell coverage area (as described above). Nevertheless, auser may prefer to handover from a macro cell to an HNB, even if thequality of the frequency of the serving macro cell is above apredetermined threshold. To handover the WTRU from a macro cell to anHNB, the network may need to configure the user's WTRU for compressedmode in order to detect the HNB primary scrambling codes (PSCs)(applicable to UMTS HNBs) or physical cell identities (PCIs) (applicableto LTE HNB) on other frequencies.

SUMMARY

Methods and apparatus for a wireless transmit/receive unit (WTRU) todetect and perform measurements with respect to Home Node-Bs (HNB) andHome evolved Node-Bs (H(e)NB) (collectively referred to as “HNB”) on afrequency and other systems are disclosed. The methods may includegenerating and transmitting a request for a measurement configurationthat may include a request for an allocation of gaps to detect andmeasure a primary scrambling code (PSC) or a physical cell identity(PCI) of a target HNB for at least one frequency or radio accesstechnology. The request may be in response to the WTRU entering a HNBcell for which the WTRU has stored fingerprint information and whoseclosed subscriber group (CSG) ID is in the WTRU's whitelist. The requestsent by the WTRU may include the frequency, fingerprint information,cell identification and other similar information. In addition, methodsare described for releasing the measurement configuration including anygaps. The network may configure the WTRU to measure the requestedfrequency or RAT in response to the vicinity/proximity report/request.

BRIEF DESCRIPTION OF THE DRAWINGS

A more detailed understanding may be had from the following description,given by way of example in conjunction with the accompanying drawingswherein:

FIG. 1 is an example of a Home Node-B (HNB) or Home (evolved) Node-B(H(e)NB) (collectively referred to as HNB) deployment in a wirelesscommunication system;

FIG. 2 is an example of a wireless communication system that may be usedwith the system of FIG. 1;

FIG. 3 is an example functional block diagram of a wirelesstransmit/receive unit (WTRU) and the Node-B of the wirelesscommunication system of FIG. 2;

FIG. 4 is another example of a wireless communication system that may beused with the system of FIG. 1;

FIG. 5 is an example functional block diagram of a WTRU and the Node-Bof the wireless communication system of FIG. 4;

FIG. 6 is an example functional block diagram of another WTRU of thewireless communication system of FIGS. 2 and 4;

FIG. 7 is an example method with respect to a WTRU entering a cell of aHNB; and

FIG. 8 is an example method with respect to a WTRU exiting a cell of aHNB.

DETAILED DESCRIPTION

When referred to hereafter, the terminology “wireless transmit/receiveunit (WTRU)” includes, but is not limited to, a user equipment (UE), amobile station, a fixed or mobile subscriber unit, a pager, a cellulartelephone, a personal digital assistant (PDA), a computer, or any othertype of device capable of operating in a wireless environment. Whenreferred to hereafter, the terminology “base station” includes, but isnot limited to, a Node-B, a site controller, an access point (AP), orany other type of interfacing device capable of operating in a wirelessenvironment. A Home Node-Bs (HNBs) and Home e-Node-Bs (HeNBs)(collectively referred to as (HNBs)) may be a WTRU, a base station or acombination thereof.

HNBs have been introduced in long term evolution (LTE) and UniversalMobile Telecommunications System (UMTS), respectively, as part of aneffort to provide improved spectral efficiency, reduced latency, andbetter utilization of radio resources for faster user experiences,richer applications and lower cost services. The HNB providessubscribers with access to network services over extremely small serviceareas, such as homes or small offices. A subscriber (e.g., an individualor an organization) may deploy a HNB over an area where such service isdesired. In general, an HNB cell may be any cell that broadcasts aclosed subscriber group (CSG) ID. The HNB cell may refer to a CSG cellor a hybrid cell. A CSG cell refers to a defined area over which radiocoverage provided by the HNB may only be accessed by a group ofsubscribers authorized, via the CSG ID, to use the services of the cell.A hybrid cell refers to a cell that has a defined area over which radiocoverage provided by the HNB corresponds to a CSG ID but which isaccessible by non-member WTRUs. HNBs may be deployed on the same carrieras open or macro base stations and may also be deployed in a dedicatedcarrier. In general, a macro cell refers to a defined area over whichradio coverage is provided by a base station (also referred to as anormal or open cell). In certain situations, the macro cell may alsorefer to a CSG cell.

Although the terminology used herein generally corresponds to UniversalMobile Telecommunications System (UMTS) technology, the conceptsdescribed herein are applicable to other wireless technologies such asLTE. Therefore, for example, if the term primary scrambling codes (PSC)is used herein, this may be considered as equivalent to physical cellidentities (PCI) in LTE. Further, the terms compressed mode gaps andmeasurement gaps are used interchangeably herein and are collectivelyreferred to hereafter as “gaps.” These “gaps” refer to the gaps that theWTRU may require to perform measurements on at least one frequency andon other systems. Additionally, the gaps may correspond to compressedmode gaps for UMTS and measurement gaps for LTE. Even further, the termCell Global Identity (CGI) may refer to the LTE CGI as well as to theUMTS Cell Identity (CI) broadcast in the system information of the cell.

To enable certain functionalities for wireless devices or wirelesstransmit/receive units (WTRUs), such as handover (HO) between networknodes, it may be necessary for the WTRU to perform measurements, forexample, of cells on a certain frequency or systems. To perform thesemeasurements, the WTRU may require a measurement configuration which mayinclude a pattern in time during which the WTRU is allowed to interruptreception on its serving cell for the purpose of performing measurementsin the same or other frequencies and other radio access technologies(RATs). Such pattern may correspond to compressed mode gaps in UMTS, ormeasurement gaps in LTE, and will be referred to as “gaps” hereinafter.

Measurement configurations may include a number of measurement typessuch as inter-frequency measurements, intra-frequency measurements, andinter-RAT measurements which assist the network for handover (HO)purposes. For both UMTS and LTE, these measurement types are configuredby the network, and the WTRU may measure on a certain frequency or radioaccess technology (RAT) if configured with such events. In some cases,in order to make measurements on at least one frequency or RAT, thenetwork has to configure the WTRU with gaps. Some, inter-frequencymeasurement report events specified in the 3GPP standards for UMTS andLTE include (assuming single-radio implementation): Event 2 a (“Changeof best frequency”); Event 2 b (“The estimated quality of the currentlyused frequency is below a certain threshold and the estimated quality ofa non-used frequency is above a certain threshold”); Event 2 c (“Theestimated quality of a non-used frequency is above a certainthreshold”); Event 2 d (“The estimated quality of the currently usedfrequency is below a certain threshold”); Event 2 e (“The estimatedquality of a non-used frequency is below a certain threshold”); andEvent 2 f (“The estimated quality of the currently used frequency isabove a certain threshold”). The measurements required to evaluate thecriteria for these events may require the WTRU to be configured withgaps.

Measurements on at least one frequency or RAT may be power consuming andmay result in some service degradation when gaps are required to takethe measurements. Therefore, by default, wireless devices may not beconfigured to measure on at least one frequency or RAT. The network mayrely on the reception of a measurement report (e.g., Event 2D), whichindicates that the quality of the currently used frequency is below athreshold. In such a situation, the network may then configure the WTRUto start taking measurements on a frequency or RAT and may additionallyconfigure the WTRU with gaps.

For LTE, the following events may be configured for an inter-frequencymeasurement type: Event A3 (Neighbor becomes amount of offset betterthan serving); Event A4 (Neighbor becomes better than absolutethreshold); and Event A5 (Serving becomes worse than absolute threshold1and Neighbor becomes better than another absolute threshold2). In atypical single-radio implementation, gaps may generally need to beconfigured to ensure a minimum time for the WTRU to performmeasurements.

Existing measurement reporting rules do not cover scenarios where it maybe preferable for the WTRU to handover from a macro cell frequency to anHNB frequency, even if the quality of the macro cell frequency is stillacceptable. The network typically configures the WTRU to measure onanother frequency or RAT when the WTRU is at the border of one or morecells and needs to handover to another cell, frequency or RAT. Giventhat for HNBs, the network is not aware of the deployment or whether aWTRU is allowed to connect to a HNB that is under the coverage of amacro cell, the network may not know when to configure the WTRU toperform HNB measurements on at least one frequency or RAT.

Disclosed herein are methods and apparatus for facilitating a wirelesstransmit/receive unit (WTRU) to detect HNBs, measure a frequency or RATwith respect to the HNB and release measurement configurations that mayinclude gaps. The methods may include generating and transmitting arequest for a measurement configuration that may include a request foran allocation of gaps to detect and measure a PSC or PCI of a target HNBfor at least one frequency or RAT. The request may be in response to theWTRU entering the proximity or vicinity of a HNB cell for which the WTRUhas stored fingerprint information (i.e., autonomous searchfunctionality) and whose closed subscriber group (CSG) ID is in theWTRU's whitelist. This may be determined in WTRU by means of WTRUspecific fingerprint information. The WTRU whitelist includes the CSGIDs of the HNBs the WTRU may be allowed to access. The request sent bythe WTRU may include the frequency, RAT, cell identification and othersimilar information. The network may then configure the WTRU to measurethe requested frequency or RAT in response to the vicinity/proximityreport/request. In addition, methods are described for releasing themeasurement configuration including gaps. The request for releasingmeasurement configuration may be in response to the WTRU leaving thevicinity of a HNB cell whose CSG ID is in the WTRU's whitelist, inaccordance with stored fingerprint information (i.e. an autonomoussearch functionality).

It is understood that the methods disclosed herein are applicable andmay be configured for inter-frequency, inter-radio access technology(RAT) and intra-frequency measurements of HNB cells or frequencies.

FIG. 1 shows an example of a HNB deployment in a wireless communicationsystem 100. The wireless communication system 100 includes an LTEopen-cell 105, a 3GPP system cell 110, a higher network node (e.g.,gateway) 115 and/or a mobility management entity (MME)/serving generalpacket radio service (GPRS) support node (SGSN) 120. The higher networknode 115 is responsible for coordinating the operation of several HNBs125A, 125B and 125C. Alternatively, the MME/SGSN 120 may be responsiblefor coordinating the operation of several HNBs 125A, 125B and 125C. TheMME is the LTE equivalent of a 3G/2G SGSN/GGSN. The relationship betweenthe LTE open-cell 105 and other 3GPP systems 110, (e.g., WCDMA/globalsystem for mobile communications (GSM)), is that there may be areaswhere the coverage of these two technologies overlap. It is similar tosimultaneous coverage of GSM and WCDMA technologies. The higher networknode 115 may be a gateway function which interfaces with the MME/SGSN120. As a gateway, the role of the higher network node 115 may be to actas a single open-cell towards the MME/SGSN 120 while supporting severalsmall home cells or CSG cells.

FIG. 2 is a block diagram of an example wireless communication system200 that works with system 100 and may include a plurality of WTRUs 210,a Node-B 220, a controlling radio network controller (CRNC) 230, aserving radio network controller (SRNC) 240, and a core network 250. TheNode-B 220 and the CRNC 230 may collectively be referred to as theUniversal Terrestrial Radio Access Network (UTRAN) 235.

The WTRUs 210 illustrated in FIG. 2 are in communication with the Node-B220, which is in communication with the CRNC 230 and the SRNC 240.Although three WTRUs 210, one Node-B 220, one CRNC 230, and one SRNC 240are shown as included in the example system 200 of FIG. 2, anycombination of wireless and wired devices may be included in a wirelesscommunication system.

FIG. 3 is a functional block diagram 300 of one of the WTRUs 210 and theNode-B 220 of the example wireless communication system 200 of FIG. 2.In general, the WTRU 210 illustrated in FIG. 3 is in communication withthe Node-B 220, and both the WTRU 210 and the Node-B 220 are configuredto detect HNBs, receive configuration information, measure at least onefrequency or RAT with respect to the HNB and release measurementconfigurations that may include gaps with respect to a WTRU entering orexiting a HNB cell. In the UMTS architecture, the SRNC sends theconfiguration information and processes the measurements.

In addition to the components that may be found in a typical WTRU, theexample WTRU 210 includes a processor 315, a receiver 316, a transmitter317, a memory (not shown) and an antenna 318. The memory may be providedto store software including, for example, an operating system,application, and other such software. The processor 315 may beconfigured to, alone or in association with the software, detect HNBs,receive configuration information, measure at least one frequency or RATwith respect to the HNB and release measurement configurations that mayinclude gaps with respect to a WTRU entering or exiting a HNB cell. Thereceiver 316 and the transmitter 317 are in communication with theprocessor 315. The antenna 318 is in communication with both thereceiver 316 and the transmitter 317 to facilitate transmission andreception of wireless data.

In addition to the components that may be found in a typical basestation, the Node-B 220 includes a processor 325, a receiver 326, atransmitter 327, and an antenna 328. The processor 325 may be configuredto, alone or in association with the software, detect HNBs, detectentering or leaving the vicinity/proximity of a HNB, receiveconfiguration information that may include gaps, measure at least onefrequency or RAT with respect to the HNB and release measurementconfigurations that may include gaps with respect to a WTRU entering orexiting the vicinity/proximity of a HNB cell. The receiver 326 and thetransmitter 327 are in communication with the processor 325. The antenna328 is in communication with both the receiver 326 and the transmitter327 to facilitate the transmission and reception of wireless data. Inthe UMTS architecture, the SRNC sends the configuration information andprocesses the measurements.

FIG. 4 shows a Long Term Evolution (LTE) wireless communicationsystem/access network 400 that may work in system 100 and may include anEvolved-Universal Terrestrial Radio Access Network (E-UTRAN) 405. TheE-UTRAN 405 includes several evolved Node-Bs, (eNBs) 420. The WTRU 410is in communication with an eNB 420. The eNBs 420 interface with eachother using an X2 interface. Each of the eNBs 420 interface with aMobility Management Entity (MME)/Serving GateWay (S-GW) 430 through anS1 interface. Although a single WTRU 410 and three eNBs 420 are shown inFIG. 4, it should be apparent that any combination of wireless and wireddevices may be included in the wireless communication system accessnetwork 400.

FIG. 5 is an example block diagram of an LTE wireless communicationsystem 500 including the WTRU 410, the eNB 420, and the MME/S-GW 430. Asshown in FIG. 5, the WTRU 410, the eNB 420 and the MME/S-GW 430 areconfigured to detect HNBs, detect entering or leaving thevicinity/proximity of a HNB, receive configuration information that mayinclude gaps, measure at least one frequency or RAT with respect to theHNB and release measurement configurations that may include gaps withrespect to a WTRU entering or exiting the vicinity/proximity of a HNBcell.

In addition to the components that may be found in a typical WTRU, theWTRU 410 includes a processor 516 with an optional linked memory 522, atleast one transceiver 514, an optional battery 520, and an antenna 518.The processor 516 is configured to detect HNBs, detect entering orleaving the vicinity/proximity of a HNB, receive configurationinformation that may include gaps, measure at least one frequency or RATwith respect to the HNB and release measurement configurations that mayinclude gaps with respect to a WTRU entering or exiting thevicinity/proximity of a HNB cell. The transceiver 514 is incommunication with the processor 516 and the antenna 518 to facilitatethe transmission and reception of wireless communications. In case abattery 520 is used in the WTRU 410, it powers the transceiver 514 andthe processor 516.

In addition to the components that may be found in a typical eNB, theeNB 420 includes a processor 517 with an optional linked memory 515,transceivers 519, and antennas 521. The processor 517 is configured todetect HNBs, detect entering or leaving the vicinity/proximity of a HNB,receive configuration information that may include gaps, measure atleast one frequency or RAT with respect to the HNB and releasemeasurement configurations that may include gaps with respect to a WTRUentering or exiting the vicinity/proximity of a HNB cell. Thetransceivers 519 are in communication with the processor 517 andantennas 521 to facilitate the transmission and reception of wirelesscommunications. The eNB 520 is connected to the Mobility ManagementEntity/Serving GateWay (MME/S-GW) 530 which includes a processor 533with an optional linked memory 534.

FIG. 6 is an example block diagram of a WTRU 600 that is configuredaccording to the embodiments disclosed herein. In addition to thecomponents that may be found in a typical WTRU, the WTRU 600 includes anantenna 605, a transmitter 610, a receiver 615, a processor 620 and auniversal subscriber identity module (USIM) (or LTE equivalent) 625. Thereceiver 615 is configured to receive a broadcast via the antenna 605from a cell including a cell ID. The processor 620 is electricallycoupled to the transmitter 610, the receiver 615 and the USIM (or LTEequivalent) 625. The processor 620 is configured to detect HNBs, detectentering or leaving the vicinity/proximity of a HNB, receiveconfiguration information that may include gaps, measure at least onefrequency or RAT with respect to the HNB and release measurementconfigurations that may include gaps with respect to a WTRU entering orexiting the vicinity/proximity of a HNB cell.

Various embodiments are described herein to detect HNBs, receiveconfiguration information, measure at least one frequency or RAT withrespect to the HNB and release measurement configurations that mayinclude gaps with respect to a WTRU entering or exiting a HNB cell. Suchembodiments may include, for example, methods that the WTRU may use torequest a measurement configuration that may include a request for anallocation of gaps so that it may detect the PSC or PCI of an HNB in itsneighborhood and/or measure its PSC or PCI on other frequencies.Embodiments for releasing the measurement configuration in addition toany gaps are also provided.

With respect to the various embodiments, two different scenarios may beconsidered. In a first scenario, the WTRU visits a certain HNB for thefirst time. In a second scenario, the WTRU subsequently encounters thesame HNB (after the initial encounter). In the second scenario, the WTRUhas already stored fingerprint information identifying the approximatelocation of an allowed HNB (e.g. a CSG that is in the whitelist of theWTRU) and may use it to determine if the WTRU is in the vicinity of anallowed HNB. Based on the outcome of the determination, the WTRU mayknow whether to measure at least one frequency or RAT. The termsvicinity and proximity may be used interchangeably herein.

In one embodiment, when such a determination is made, the WTRU may senda request (e.g., a report) to the network notifying the network of thevicinity of this HNB. This may be use to send a request (e.g., a report)to the network to perform measurements of CSG cells in the neighborhoodor in the vicinity of a given frequency or RAT. In order to allow theWTRU to request such measurement configurations, new measurement reporttypes (such as for inter-frequency or inter-RAT) or events may beintroduced. In one option, the WTRU may introduce two events. Oneexample of an event or measurement type may, for example, be for thefirst scenario where the WTRU is in the vicinity of an inter-frequencyHNB for the first time and, as a consequence, does not have a storedfingerprint for the HNB. Another example event or type may, for example,be for the second scenario, where the WTRU is aware that an allowedneighboring HNB is present in a frequency or RAT due to storedfingerprint information.

For instance, in the first scenario, where the WTRU does not have thecapability to determine whether it is within the coverage of an allowedHNB or not, the WTRU may introduce a new event or report with thedescription “Request for gaps for detecting inter-frequency HNBs.” Forexample, in UMTS, this event may be called event 2 g. For LTE, the eventmay be called event A6. Although this event is referred to as event 2 gor A6, it may take any other number, name or type. Although the term“Request for gaps . . . ' is used in the example, it may alternativelybe a “Request for measurement configuration . . . ” or “Request formeasurement configuration and gaps . . . . ”

This new event/report may be triggered as a result of the initiation ofa manual HNB search, which may now be allowed in connected mode. Becausethe WTRU is in connected mode (e.g., CELL_DCH), it cannot measure afrequency without service interruption. Therefore, once a manual searchis initiated, the WTRU may trigger event 2 g to indicate to the networkthat it would like to measure an HNB frequency (if the network hadpreviously configured the WTRU with a measurement command for thisevent). The network may then configure the WTRU with gaps, and,accordingly, the WTRU may detect the HNB PSC (or PCI) on at least onefrequency (if any are available). Although the CELL_DCH is shown as anillustrative state, the methods and apparatus described herein are alsoapplicable to WTRUs in the CELL_FACH state.

The event 2 g may be triggered in other ways in addition to beingtriggered by a manual search. For example, the event 2 g may also betriggered by a location-type detection when the WTRU is equipped with aGPS. For example, if the WTRU detects that it entered a city area (orany specific preferred HNB area); it may send an event 2 g to thenetwork. Otherwise, no event is triggered. By way of another example,the event 2 g may be triggered by a periodic search for HNBs defined inthe WTRU (e.g., upon expiration of a timer). The duration of this timermay be fixed or configurable by the network or a user. According to thisexample, once the timer expires, the WTRU is triggered to perform an HNBsearch in the current frequency (and, optionally, in at least onefrequency and system). The event for requesting gaps may also betriggered if the WTRU detects that a desired PSC or PCI (oralternatively HNB) is in a neighboring list provided to the WTRU.

It may also be possible for the WTRU to perform measurements on the HNBfrequency without using any measurement or compressed mode gap. This mayoccur when, for example, the WTRU is configured with Continuous PacketConnectivity (CPC) Discontinuous reception (DRX) (for UMTS) in CELL_DCHor with DRX in LTE and there is little traffic activity. In this exampleembodiment, event 2 f or 2 g may optionally be triggered only if theWTRU does not detect the PSC or PCI of the HNB after a timer expires(e.g., the timer may have been started responsive to the manual searchrequest or detection of a matching fingerprint). Such a timer may bestopped if/when the WTRU detects the PSC or PCI of the HNB (e.g., due toDRX opportunities). In another option, the timer may also be stoppedafter a pre-defined or pre-signaled inter-frequency measurement duration(performed during DRX opportunities) has elapsed.

Optionally, as part of the new measurement event, the WTRU may indicatethe reason why it was triggered, such as manual search, periodic searchby the WTRU, location and the PSC/PSI in neighboring list. Theneighboring list may be provided by the network and includes thePSCs/PSIs of the cells located in the neighborhood of the WTRU. Asstated above, the whitelist may contain the CSG IDs of the HNBs the WTRUmay be allowed to access. A neighbor cell may or may not have its CSG IDas part of the WTRU whitelist.

In the second scenario, if the WTRU detects, using stored fingerprintinformation, that at least one of the HNBs with a CSG ID stored in itsUniversal Subscriber Identity Module (USIM) or whitelist may potentiallybe using a same of different frequency or different RAT than the servingmacro cell and is close to its current location (in the proximity of themacro cell), the WTRU may introduce, trigger and send to the network anew event/report/message indicating that a CSG is in the proximity(e.g., the WTRU is entering an area in which a CSG whose CSG identity isin the WTRU's whitelist may be available). Upon reception of thisreport, the network may configure the WTRU for measurements, optionallyusing gaps, so that the WTRU may measure the PSCs or PCIs correspondingto the HNBs on the applicable frequency(ies).

The new report may correspond to a new event within an existingmeasurement type (e.g., inter-frequency type, group 2 x or Ax) and maybe called, for example, event 2 h for UMTS and A7 for LTE and may beentitled “One or several HNBs on a different frequency match the currentWTRU location.” Alternatively, the same event/report may be used forboth the first and second scenarios described above. The event may, forinstance, be consolidated in one event (e.g., event 2 g for UMTS and A6for LTE). The event may be triggered based on any of the individual orcombined conditions described above.

In another embodiment, the WTRU may use an existing event to report apreference to measure a neighboring HNB in a frequency, even if theestimated quality of the currently used frequency is above a certainthreshold. This may be achieved for UMTS, for example, by extending anexisting event, such as event 2 f. Extending the event may be performed,for example, by adding a one bit information element (IE) (such as aflag) indicating that the event was triggered for HNB and that the WTRUmay like to measure an HNB on a different frequency or system. For UMTS,the additional IE may be added in any IE, such as measurement reportstructures, event results, Inter-Frequency event results and extensionsto sub-IEs containing event 2 f information. For LTE, the additional IEmay be added, for example, as a non-critical extension of theMeasurementReport message or of the measResults IE.

In another embodiment, the WTRU may use a new type of measurement groupto notify the network about HNB related events as described herein.These HNB events within a new measurement type may, for example, bereferred/configured as measurement type 8, and be referred to as CSGreporting type. For example, 8 x events for UMTS and Cx events for LTEmay be defined. These new measurement types may be used for frequency orRAT measurements. For example, the WTRU may use new event 8 a (“requestof gaps for detecting inter-frequency PSC) to request gaps.Alternatively, the WTRU may introduce two new events such as, forexample, 8 a and 8 b. One of the new events may be used for the firstscenario where the WTRU has no fingerprint information, and the othermay be used for the second scenario where the WTRU has fingerprintinformation (similar to 2 g and 2 h, for example). Two separate eventsmay be defined for inter-frequency and inter-RAT requests for PSCdetection. Alternatively, one event or measurement type may be used forboth frequency and RAT requests. This common measurement type is used bythe WTRU to report to the network that it has detected that an allowedCSG is in the vicinity of the current location.

Alternatively, a new Radio Resource Control (RRC) message may be definedvia which the WTRU may use to report CSGs in the vicinity. This newmessage may carry the same information described above for the otherembodiments.

While the above embodiments are described in the context ofinter-frequency measurements, they are equally applicable for requestinggaps to detect HNBs for the inter-RAT scenarios as well (e.g., if theWTRU attempts to measure and handover from a UMTS macro cell to an LTEHeNB) and intra-frequency scenarios. It should also be understood thatthe triggering criteria may be similar to the inter-frequency scenario.In the inter-RAT case, a new inter-RAT event may be added (e.g., event 3e for UMTS and B3 for LTE, “Request of gaps for detecting HNBs onanother system”). Alternatively, a new event from the new HNB events maybe defined (e.g., 8 x for UMTS or Cx for LTE, “Request of gaps fordetecting other system's HNBs”). An existing 3 x event may alternativelybe reused as described herein.

The new event/report as part of the new measurement type, 8 may be thesame one used for the inter-frequency case. For example, one event 8 aor one report may be used for “Request of gaps for detecting HNBs” or(using the same terminology as above), “One or several HNBs match thecurrent WTRU location”. In this case, once the event/report istriggered, it may also contain an optional information elementindicating whether the WTRU wishes to perform measurements oninter-frequency, inter-RAT, or both.

In general, the network may use the information provided by the WTRU todetermine whether measurement configurations that may include gapsshould be allocated and also the duration of the gaps, if needed. Theduration of the gaps, for example, may depend on the number offrequencies the WTRU has to measure.

Optionally, a new IE may be added in the report to indicate the reasonwhy the event report was triggered. This may include, by way ofnon-limiting example, one, or a combination of, a manual search, aperiodic search by the WTRU, a location, a fingerprint matches thefingerprint of at least one HNB stored in the WTRU whitelist, and a PSCis in a neighbor list. This may be combined with any of the embodimentsdescribed herein.

In another embodiment for triggering proximity indication reporting, aLTE macro cell connection may have a higher priority than the UMTS HNB.Although described with respect to a LTE macro cell and an UMTS HNB, thedescription herein is applicable to other RAT combinations of macrocells and HNBs. In this embodiment, if a WTRU is connected to a LTEmacro cell and it detects by means of its stored fingerprint informationthat it is close to a UMTS HNB that it is a member of, the WTRU does notnecessarily trigger an autonomous search, (i.e., it does not send a HNBproximity indication to the network). The autonomous search may beinitiated in such circumstances, only if the LTE macro cell channelconditions are deteriorating (i.e. the channel quality falls below agiven threshold). The conditions to trigger a search and a measurementreport to indicate a proximity indication may occur if 1) the currentmacro serving cell is LTE; 2) one of the WTRUs stored fingerprintsmatches a UMTS HNB (i.e., a UMTS HNB is in the WTRU's proximity); and 3)the macro serving cell quality is below a certain threshold. Thisthreshold may be configured by the network, may be a fixed value used bythe WTRU or may be determined by the WTRU. It may be a common value or avalue per cell.

If these conditions are met, then the WTRU may send a measurement reportto the network in order to request a measurement configuration that mayinclude gaps for detecting the PSC and acquiring a master informationblock (MIB) (with optionally a Scheduling Block and a system informationblock 3 (SIB3) of the UMTS HNB. If conditions 1 and 2 are fulfilled andcondition 3 is not, the WTRU may not send any report to the network totrigger the HNB measurements.

Optionally, the WTRU may still autonomously measure the channel qualityof the PSC of the UMTS HNB that is in the WTRU's proximity and triggerthe search if the PSC of the UMTS HNB is above a threshold. This optionmay be for a configured period of time. This trigger may be used incombination with the other triggers described herein.

Described now are examples for the information contained in the report.

Optionally, as part of the report, additional information may bereported to the network (if available to the WTRU), including, by way ofnon-limiting example, one, or a combination of, the known frequency ofthe HNB(s) which triggered the proximity report and whose CSG is storedon the whitelist of the WTRU, and/or the known RAT of the CSG(s) cellwhich triggered the report (e.g., LTE or UMTS).

The WTRU may optionally also include the following informationpertaining to the CSG(s) which triggered the report such as, the knownHNB's PSCs/PSIs of the CSG(s) cells stored on the whitelist of the WTRU,and the WTRU CSG IDs part of the whitelist. The WTRU may also include aCGI in the report sent to the network. Such additional information maybe useful to the WTRU for detecting a “false” fingerprint match (e.g.,where the WTRU determines that an HNB included in its whitelist is inits vicinity, but this is not actually the case). In this example, ifthe eNB or RNC receives a CGI in the gap request report, it may verifythat an HNB with the corresponding CGI actually exists. If, however, itdoes not recognize the CGI, the eNB or RNC may decide to not configurethe WTRU with a measurement configuration. Accordingly, if the WTRU doesnot receive a gaps configuration (or other measurement configuration)from the network within a certain period of time after requesting thenetwork to configure it for measurement and/or gaps, the WTRU may decideto delete the corresponding fingerprint from its memory to avoidunnecessary gaps requests in the future. Alternatively, or in addition,the network (e.g., the eNB or the RNC) may explicitly indicate to theWTRU that a cell having a CGI corresponding to the CGI that the WTRUreported does not exist. Using this information, the WTRU may thendelete the corresponding fingerprint as in the previous example. Thenetwork may also use the CSG ID information (if provided by the WTRU)for a similar purpose.

Optionally, in a deployment where the network is aware of all CSG cellfrequencies in the vicinity and realizes that no CSG cell correspondingto the CSG cell reported by the WTRU as part of its whitelist isavailable, the network may not allocate any gaps. Instead, the networkmay, optionally, send an RRC message (for example, a measurementcontrol) back to the WTRU indicating that no such CSG cell is availableand that the WTRU does not have to measure inter-frequency HNBs. TheWTRU may then update its HNB fingerprints accordingly.

Optionally, together with the proximity indicator, the WTRU may signalthat a given HNB that is in the WTRU's proximity has priority. This mayassist the network in allowing the WTRU to measure the HNB andpotentially providing a measurement configuration that may include gaps.

The network may need to explicitly release measurement configurations orgaps that it allocated to allow the WTRU to detect HNB PSCs/PCIs on afrequency or RAT in case, for example, no handover occurs. Differentcauses may trigger the interruption/release of the measurementconfiguration which may have included gaps, such as, for example: theWTRU did not detect (and therefore did not report to the network) an HNBPSC after a certain period of time; the quality of the detected HNBs ina frequency or other system is below a certain threshold; the WTRU onlydetected HNB PSCs that are not on its whitelist; the WTRU detected thatit is leaving the vicinity of its allowed HNBs (e.g., a HNB whose CSG isin the WTRU's whitelist) using its stored HNB fingerprints (e.g., thereis no longer a matching fingerprint); the WTRU measured, but did notfind, any HNBs with the CSG IDs in its whitelist; and no acceptable HNBswere detected.

The network or the WTRU may trigger release of the gaps. For example, ifthe network does not receive any HNB PSCs reported by the WTRU after acertain period of time, it may reconfigure the WTRU for deactivating thegaps. Alternatively, if the network knows the WTRU's location andrealizes that no inter-frequency HNB is located in the WTRU'sneighborhood, it may also release the gaps in the WTRU. The WTRU mayrelease the gaps according to any of the following embodiments.

In one embodiment, the WTRU may notify the network that it no longerrequires a measurement configuration (e.g., notify the network that itis leaving the area where there might be an allowed CSG cell). Uponreception of this notification, the network may reconfigure the WTRU toremove the measurement configuration, and optionally the gaps for theWTRU. When referred to hereafter, releasing the gaps refers to releasingthe measurement configuration for CSG cells, or removing theconfiguration.

This notification/report may be sent via a new inter-frequency event.For example, for UMTS it may be type 2 i, “Request for releasing thegaps allocated for detecting inter-frequency HNB”.

Alternatively, the WTRU may use the new measurement type for CSGreports, e.g., 8. A new event/cause for reporting this event may bedefined. As an example this may be called event 8 b (or C2) “Request forreleasing gaps for detecting inter-frequency HNB,” to ask the network torelease gaps (e.g., 8 x for UMTS or Cx for LTE as described in theprevious section). It is understood that the naming of events/triggercauses are illustrative and any names or descriptors may be used. Forexample, when the trigger corresponds to “the WTRU detected that it isleaving the vicinity of its allowed HNBs (e.g., a HNB whose CSG is inthe WTRU's whitelist)”, then the WTRU cause may be referred to as “theWTRU is leaving the CSG area”.

In another embodiment, the WTRU may release the gaps autonomously,without waiting for a reconfiguration message from the network after itdetects that it no longer needs to measure inter-frequency HNBs. TheWTRU may also notify the network that it has released the gaps with anew event, such as event 2 j fro UMTS, “Gaps allocated for detectinginter-frequency HNB have been released.” Alternatively, the WTRU may usean HNB event type, for example, 8 x for UMTS or Cx for LTE, as describedherein. The new event may be called, for example, 8 c (or C3) “Gaps fordetecting inter-frequency PSC have been released.”

In another embodiment, the WTRU may re-use an existing measurementreport event type and add to it a new IE to inform the network that thegaps previously allocated for detecting HNBs on other frequencies haveto be released. Alternatively, this new IE may indicate to the networkthat the WTRU has autonomously released its gaps. For example, for UMTS,the event 2 f may be modified as such with a new optional IE of typeenumeration indicating one of a request for releasing gaps allocated fordetecting inter-frequency HNB or a notification that the WTRU hasreleased the gaps allocated for detecting inter-frequency HNB.

The WTRU may add an IE in the measurement report describing why itreleased the gaps. The IE may indicate, for example, that theInter-frequency HNB search timer has elapsed or that the stored HNBfingerprint does not match.

Alternatively, a new RRC message may be defined and used by the WTRU torequest or notify the network that one of the triggers described abovehas been met. For the trigger, wherein the WTRU detected that it isleaving the vicinity of its allowed HNBs (e.g., a HNB whose CSG is inthe WTRU's whitelist), the new RRC message used indicates to the networkthat the WTRU is leaving the area. This new message may carry the sameinformation as described above for the other embodiments. This RRCmessage may be a new message or the same RRC message used to indicatethe request for initial measurements (e.g. when the WTRU enters thevicinity of a CSG cell).

The embodiments described herein for releasing the measurementconfiguration and any gaps previously allocated for detectinginter-frequency HNBs, may also be used for the inter-RAT (IRAT) scenarioas well. For example, the WTRU may try to handover from a UMTS macrocell to an LTE HeNB. In the IRAT case, a new IRAT event may be added.For instance, event 3 f for UMTS and event B4 for LTE, “Request forreleasing gaps allocated for detecting HNBs of other system,” may beadded or a new event from the new HNB events 8 c “Request for releasinggaps allocated for measuring other system” may be defined.Alternatively, a common event may be used as 8 x (e.g., 8 b) to notifythe network that the measurement configuration and any gaps may nolonger be needed. The common event may be used for both inter-frequencyand inter-RAT measurement configuration and gap release when a WTRUleaves a HNB cell.

Optionally, the gaps may also be released once a handover to a HNBoccurs.

Although the CELL_DCH is shown as an illustrative state, the methods andapparatus described herein are also applicable to WTRUs in the CELL_FACHstate. In other connected mode states, such as CELL_FACH states, similarmessages as the ones described for CELL_DCH may be used to notify thenetwork.

It is understood that these methods are also applicable to otherconnected mode states such as CELL_FACH, even though CELL_DCH messagesare shown above as illustrative states. The messages used to notify thenetwork as described herein for CELL_FACH state may be similar to theones described above or optionally, in the CELL_FACH state the WTRU mayuse messages such as CELL UPDATE to notify the network. A new cause orinformation element may be used by the WTRU to indicate the reason why aCELL UPDATE Message is being sent (e.g., entering or leaving thevicinity of a HNB).

One or a combination of the following example methods may be implementedin order to prevent the WTRU from requesting gaps too frequently.

In an example method, the WTRU may not be allowed to request gaps fordetecting HNB PSC/PCI more than a certain number of times during acertain period of time. The periodicity (e.g., number of times andperiod of time) may be signaled by the network, may be part of thebroadcast information, or stored in the WTRU. Optionally, thisperiodicity may differ per HNB. For example, the periodicity may be highfor the user's home HNB, while low for other HNBs. This periodicity mayalso depend on the user's mobility.

In another example method, the network may be aware that there are noHNBs in the WTRU's vicinity and may indicate to the WTRU in an existingsignal (e.g. new IE added in measurement control) that it is not allowedto request gaps (or triggering proximity reports) for detecting an HNBPSC/PCI.

In another example method, the network may indicate to the WTRU in anexisting signal that only gap requests based on fingerprint matches areallowed and that periodic requests are forbidden.

In another example method, the fingerprint information in the WTRU maybe maintained to make sure it is valid when the WTRU uses it to requestgaps (i.e., to make sure there is an allowed HNB in the WTRU'sneighborhood). This may be implemented using one or a combination of thefollowing methods.

In one example implementation, a validity timer per HNB fingerprint maybe started when the fingerprint is stored in the WTRU. When this timerexpires the WTRU may delete the fingerprint associated to the HNB.

In another example implementation, a periodic timer may be used todelete periodically all the HNB fingerprints stored in the WTRU.

In another example implementation, the network may request the WTRU todelete one or a list of all the HNB fingerprints the WTRU has stored bysending an RRC message to the WTRU.

In another example implementation, in case the handover to a particularHNB is rejected by the network, the WTRU may delete the associatedfingerprint.

Described herein are embodiments for HNB PSC detection via transmission.In one embodiment, the inter-frequency PSC (or PCI) detection may beperformed via the HNBs' transmissions of the common pilot channel(CPICH) on the serving macro cell frequency (or transmission of primaryand secondary synchronization signals (PSS and SSS) for LTE). In thisembodiment, only the CPICH (for UMTS) or PSS/SSS (for LTE) istransmitted, without any of the System Information Blocks (SIBs). Thesignals necessary to detect a PSC or PCI (CPICH for UMTS, PSS/SSS forLTE) are transmitted by the HNB on the serving macro cell frequency.Optionally, in addition to the CPICH, the master information block (MIB)indicating the frequency of the HNB and that the cell is a HNB cell maybe broadcast. The WTRU performing intra-frequency measurements maydetect the PSCs and, therefore, may request gaps from the network toperform additional measurements on the HNB's corresponding frequency (ifknown from signaling from the macro cell or otherwise indicated). If itis not known from the macro cell's signaling or from other indications,the WTRU may have to rely on fingerprint information or even measure onall other frequencies.

The gaps may be requested on one, or a combination of, the followingconditions: the WTRU detects HNB's PSCs (or PCIs); the WTRU detects anHNB PSC (or PCI) that is in its whitelist; the WTRU detects an HNB PSC(or PCI) that is contained within a known fingerprint location; the WTRUperforms a manual search and detects that there are HNBs in theneighboring frequencies; the WTRU performs a periodic search; the WTRUdetects an HNB PSC (or PCI) that is in a reserved PSC or PCI range ofhybrid cells; and the WTRU detects an HNB PSC (or PCI) that is in areserved PSC range or PCI range of CSG cells.

Signaling of supported HNB PSC/PCI detection methods on inbound mobilitysupport are disclosed hereinafter.

The different HNB PSC/PCI detection methods disclosed herein may befully or only partially supported by the WTRU. The WTRU may indicate tothe network which methods it supports by adding new IEs in existing RRCmessages (for example, in the RRC Connection Request or the RRCConnection Setup Complete) or in a new RRC message. One or a combinationof the following capabilities may be indicated by the WTRU to thenetwork: a) WTRU capable to request for gaps for detecting HNB PSC/PCIon a frequency (e.g. inter or intra-frequency to the same RAT as themacro cell); b) WTRU capable to request for gaps for detecting HNBPSC/PCI in a different RAT; and c) WTRU capable to detect PSC/PCI ofinter-frequency HNB transmitting their CPICH for UMTS or PSS/SSS for LTEon the serving macro-cell frequency. As described above, requesting gapsmay correspond to the capability of detecting that you are in thevicinity or proximity of a CSG cell whose CSG belongs to the WTRU'swhitelist.

In addition, the network may deactivate any of the supported methodsmentioned hereinabove in the WTRU by explicit signaling.

Even if the WTRU supports the above mentioned capabilities, the networkalso needs to support this mobility procedure. In general, the WTRU andnetwork both need to support mobility in the case where a WTRU enters orexits the vicinity or proximity of a HNB. As described herein, the WTRUmay request or enable the detection and triggering of requests formeasurement configurations and any gaps or trigger events if the WTRUknows that the network supports inbound mobility and the WTRU alsosupports it.

In order to determine that the network supports inbound mobility andmore specifically the triggers described above, one or a combination ofthe following methods may be used. For illustrative purposes, inboundmobility may refer to the ability to detect proximity to a HNB and tosend/receive reports/events in response to the proximity detection, forexample, when the WTRU enters/exits the vicinity (proximity) of the HNB.In one example method, the events to trigger detection mechanisms forinbound mobility are configured by the network via measurementcontrol/configuration messages. If such measurement types or events arenot configured (e.g., not present in the configuration messages), theWTRU determines that inbound mobility detection is not supported.Depending on the measurements that are configured, the WTRU implicitlydetermines whether inter-frequency, inter-RAT or intra-frequencymobility is supported. For example, in the case where a new measurementtype, 8, is introduced as described above, inter-frequency orintra-frequency CSG detection mechanisms can be configured for a certainRAT. If not configured then the WTRU determines that the network doesnot support inbound detection mechanism for the given RAT and thereforedisables the functionality.

In another example method, the network explicitly signals to the WTRUupon RRC connection procedures, that inbound mobility to HNBs issupported. If the WTRU moves to an area where inbound mobility is notsupported, the network may inform the WTRU of the change of capability.

In another example method, the network may explicitly indicate whetherinter-frequency inbound mobility is supported, whether inter-RATmobility is supported, or whether intra-frequency inbound mobility issupported. In the case of inter-RAT mobility, the network may alsoexplicitly indicate whether just LTE to HNB UMTS mobility is supported,UMTS to LTE HNB mobility is supported or any inter-RAT mobility issupported.

Events similar to the ones described above may also be used, wherein theWTRU may provide the network with any of the information describedabove.

FIG. 7 illustrates a method 700 for implementing the examples andembodiments described herein in the case of a WTRU entering the cell orfrequency of an HNB. Upon entering the cell or frequency of the HNB, theWTRU and network perform a capability exchange to determine if inboundmobility is supported by the WTRU and network. The network may need toconfigure the WTRU with the events that trigger the measurements. TheWTRU detects via, for example, fingerprint information that it hasentered into the vicinity of an HNB cell whose CSG ID is in the WTRU'swhitelist (705). The WTRU then indicates to the network that it hasentered the vicinity of a HNB whose CSG ID is in its whitelist (715).The indication or request message may include HNB information, such asthe frequency or RAT for the HNB which triggered the report. Theindication or request message may be sent via a radio resource control(RRC) message or a Measurement Report. The Measurement Report maycontain the proximity indication. The WTRU then receives from thenetwork, base station or other similar entity as determined by systemarchitecture or structure, a measurement configuration message that mayinclude gaps and the PSCs/PCIs to measure (725) and performs themeasurements to detect the PSC or PCI (735). The WTRU may then send ameasurement report to the base station (745). The measurement report mayinclude an Information Element (IE) containing, for example, a detectionresult, measurement results for the cells that are on the frequencyadded by the measurement configuration and a triggering of an existingmobility event such as, for example event type 1D or 1A.

FIG. 8 illustrates a method 800 for implementing the examples andembodiments described herein in the case of a WTRU exiting the cell orfrequency of an HNB. As in FIG. 7, a capability exchange may beperformed between the WTRU and the network including the sending ofconfiguration information for the events that trigger the measurements.Initially, the WTRU detects, via for example, the use of fingerprintinformation, that it is exiting the vicinity of an HNB cell whose CSG IDis in the WTRU's whitelist (805). The WTRU then indicates to thenetwork, base station or similar entity that may be dependent on system,that it is leaving the HNB area (e.g., that it may no longer need themeasurement configuration or gaps allocated to acquire the HNB's PSCs orPCIs) (815). The indication or request message may be sent via a radioresource control (RRC) message or a measurement report. The WTRU thenreceives from the network, base station or similar entity that may bedependent on system, a configuration message to release the measurementconfiguration, which may have included gaps (825) and the WTRU thenreleases the configuration (835).

Described herein are additional embodiments. In an example embodiment,the WTRU may be configured for discontinuous reception (DRX) and mayhave enough idle periods to detect the PSC and read the systeminformation of the HNB. The WTRU may start the handover procedureevaluation if the macro cell quality is good. A limit on the durationduring which the WTRU tries to acquire the SIBs may be applied in orderto limit the power usage of the WTRU. For example, the WTRU may stop theinter-RAT handover procedure when a timer expires.

In another embodiment, in case event B1 is configured by the network,where event B1 is “Inter-RAT neighbor becomes better than threshold”,the WTRU may not report or may not trigger the event in case it isconnected to, for example, a LTE macro cell, and the inter-RAT neighborcell that is becoming better than a threshold is, for example, an UMTSHNB. In this instance, the LTE macro cell may have a higher prioritythan the UMTS HNB. If the WTRU detects that the PSC corresponds to aHNB, the WTRU may trigger the measurement report indicating the event B1and additionally signal a proximity indication. The proximity indicationmay be added to the same measurement report or to a differentmeasurement report that may be used to initiate autonomous search in theWTRU. As indicated earlier, the roles of the specific RATs may beinterchanged in the examples and are used herein as illustrativeexamples.

This new restriction about inbound mobility from the macro LTE cell toan UMTS HNB, may prevent the user who owns a LTE capable WTRU but has aUMTS HNB, to handover to the UMTS HNB if the UMTS HNB is in the coverageof the LTE macro cell. One method for connecting to the UMTS HNB wouldbe to drop the connection to the LTE macro cell so that the WTRU maycamp on the UMTS HNB in Idle mode. Alternatively, if the user wants toswitch to the UMTS HNB while in connected mode, an optional indicatormay be added in the fingerprint information stored for the UMTS HNB thatwould force the WTRU to perform an inter-RAT handover or initiate anautonomous search from a LTE macro cell to this particular UMTS HNB. Forinstance, the flag in the fingerprint information may be used as anabsolute priority indicator for the UMTS HNB. In this instance, nomatter what RAT or frequency the WTRU is connected on, the HNB takespriority over all the other macro cells and therefore an autonomoussearch is triggered and the proximity indicator is signaled to thenetwork. Additional information may be added in the proximity indicationincluding the RAT and the priority associated with the RAT.

In another example method, such inter-RAT autonomous search or handovermay also be initiated by the user using a manual search even if theconditions described earlier to measure the HNB in the other RAT havenot been met. In such cases, if the WTRU detects that a search has beeninitiated, and the WTRU has a stored HNB on another RAT in itsfingerprint information, the WTRU may immediately attempt to decode theNB that is in its fingerprint information. Optionally, the manual searchby the user may trigger the WTRU to decide that a proximity indicationin a measurement report may be sent to the network to initiatemeasurement and detection of the HNB even if the conditions discussedabove have not been met. In this method, the manual trigger by the usermay overrule the set priorities between the RATs and HNBs.

In another example method, it may be specified that the WTRU givespreference to a member HNB on a different RAT than the serving macrocell. This preferential treatment may occur when the HNB is using thesame RAT as a reference HNB that may include, for example, a HNBinstalled at a user's home or any HNB as indicated by the user. Thereference HNB may be indicated in the fingerprint information stored inthe WTRU. The rules for restricting the inter-RAT inbound handover mayinclude fulfilling the following conditions: 1) current macro servingcell is on a different RAT than a target HNB; 2) target HNB, using adifferent RAT than the reference HNB, matches fingerprint informationstored in the WTRU; and 3) macro serving cell quality is below a certainthreshold. This threshold may be configured by the network, may be afixed value used by the WTRU or may be determined by the WTRU. Thethreshold may be a common value or a value per cell. Optionally, theconditions may need to persist for a given period of time.

If all three conditions are met, then the WTRU sends a measurementreport to the network in order to request a measurement configurationthat may include gaps for detecting the PSC/PCI, acquiring the systeminformation or to ask for the authorization to use autonomous gaps. Ifonly conditions 1 and 2 are met, the WTRU may not send any report to thenetwork to trigger the HNB measurements. Alternatively, the WTRU maystill send a measurement report indicating that the proximity indicationcorresponds to a HNB and may include in the measurement report the RATof the HNB. The network may chose to allow the WTRU to start searchingand measuring the HNB belonging to a RAT other than the macro servingcell upon explicit indication from the network.

In another example method, priorities between the RATs and HNBs may beexplicitly set by the network. The network may explicitly indicate tothe WTRU that a LTE macro cell and/or LTE HNB have priority over a UMTSHNB. The WTRU, therefore, may initiate a UMTS HNB search (that is in itsproximity) if the quality of the LTE macro cell or LTE HNB goes below athreshold as described above. Other examples may include a LTE HNB thatmay have priority over a UMTS macro cell or vice versa.

Priority indication for mobility between a macro cell on one RAT and aHNB in another RAT may be different than inter-RAT priority for macrocell to macro cell mobility. For instance, even if LTE has higherpriority for inter-RAT macro cell to macro cell, the same rules may notbe applicable if a UMTS HNB is in its vicinity. In such a case, eitherthe UMTS HNB may have been signaled to have higher priority or byimplicit rule it has higher priority. If no priority indication has beensignaled for the HNB in the other RAT, the WTRU may assume: 1) that theHNB has priority as for normal inbound mobility cases; 2) that the HNBin the other RAT will inherit the same inter-RAT mobility priorities asthe ones indicated for macro cell to macro cell rules; or 3) it will actaccording to one of the rules described above. The HNB priority settingdescribed herein may also be applicable for HNB to macro cell prioritieswithin the same frequency.

The inbound HNB priority indication (which may be applicable tofrequency or RAT) may be set for all CSGs belonging to a RAT orfrequency or may be set on a per CSG basis. Upon successfulregistration, the priorities of the CSG and the RAT may be set andoptionally updated later. For instance, for some CSGs (e.g., the user'shome CSG), the network may prefer that the WTRU try to connect to thisCSG even if the WTRU is camped/connected to the other frequency or RAT.However, for some CSGs the network may prefer that the WTRU does notconnect to this CSG (i.e., only connects if the quality of the currentmacro cell is below a threshold).

Alternatively, absolute HNB RAT priorities and optionally absolutefrequency priorities may be signaled. For instance, the network mayassign different RAT priorities. For example, if the detected HNB has aHNB RAT priority higher than the RAT or frequency the WTRU is connectedto, the WTRU may initiate an autonomous search in an effort to connectto this HNB. If the detected HNB is in a lower priority HNB RAT, it maystart autonomous search if the quality of the current RAT or frequencyis below a threshold. The thresholds described in this disclosure forthe current connected RAT, may be similar to thresholds used for normalinter-RAT mobility or alternatively HNB specific thresholds which may beless strict and may allow the WTRU to connect to the HNB earlier. Thepriorities may be indicated by signaling or in the broadcasted systeminformation.

In general, when a HNB in the WTRU's proximity has a higher prioritythan the current macro cell (according to priorities set with respect toany frequency and/or RAT as described above), the WTRU may initiate anautonomous search (e.g. try to perform a handover to this HNB). Theautonomous search, for example, may comprise the transmission of ameasurement report and/or proximity indication to the network and/orattempt to read SI. If this HNB has a lower priority than the currentRAT, an autonomous search may be triggered if the quality of currentmacro cell is below a threshold and optionally, if the quality is belowa threshold for a configured amount of time. This criteria is similar tothe criteria described above for fixed priority settings.

In certain situations, there may be an abundance of opportunities forinter-RAT inbound handover attempts. For example, users may purchase aHNB for one RAT and then upgrade to another HNB with a different RAT. Inother situations, they may have WTRUs for one RAT and a HNB on anotherRAT and then decide to buy the HNB of the same technology as the WTRU.In addition, some WTRUs may be multiple RAT capable while other WTRUsmay be single RAT. These situations may lead to many inter-RAT inboundhandover attempts by the WTRU. This may be undesirable due to excessivebattery usage and service degradation. In order to limit the number ofhandover evaluation procedures when the user is a macro cell coverageand moves between HNBs of different RATs, the WTRU may use a specialCSG-inter-RAT Time to Trigger longer than the timer configured by thenetwork. Alternatively, there may be a CSG inter-RAT offset added to theconfigured time to trigger. In these cases, when a fingerprint matchoccurs the event report is therefore not triggered too quickly. Sincemost HNBs are deployed for service enhancement purposes, it isacceptable that the WTRU stays connected on the macro cell for a longerperiod of time in order to limit unnecessary inter-RAT inboundhandovers. For example, if the following conditions are fulfilled: 1)the WTRU is connected to a macro cell of a certain RAT; 2) the WTRUdetects a fingerprint match for a HNB of a different RAT; and 3) theWTRU verifies that the HNB quality is above a certain CSG-inter-RATthreshold during the CSG-inter-RAT Time To Trigger duration, then theWTRU may report a measurement event for this HNB to the network.

If conditions 1 and 2 are met but condition 3 is not met and if thequality of the macro serving cell is not acceptable (e.g., below acertain threshold), the WTRU may also report a measurement event forthis HNB to the network. Otherwise the WTRU does not send a measurementreport and remains connected to the macro serving cell.

The CSG-inter-RAT Time to Trigger may be used by the WTRU whenevaluating inter-RAT events B1, B2 for LTE, 3A, 3C events for UMTS, ornew events specified for HNB. The CSG-inter-RAT threshold may beconfigured by the network, but may also be a threshold determined by theWTRU so that the WTRU may give a certain preference to member HNBs.

Alternatively, condition 3 may be deleted and condition 2 may bereplaced by an alternative condition 2, where the WTRU may detect afingerprint match for a HNB on a different RAT and this fingerprintmatch is verified during the CSG-inter-RAT Time To Trigger duration. Inthis alternative, there may not be any condition on the HNB signalquality, but it is assumed that in case of a fingerprint match thequality of the HNB should be good.

In another implementation, it may be specified that the WTRU has to stayconnected to the macro serving cell for a certain period of time beforeit may trigger an event to start the inter-RAT HNB handovermeasurements. The timer duration may be signaled by the network, or maybe a pre-determined value known by the WTRU. It may also be a valuestored in the fingerprint information per HNB so that the WTRU may behanded over to certain HNBs faster than for others. If the timer has notexpired yet, but the serving macro cell quality is not acceptableanymore (e.g., below a certain threshold), the WTRU may be allowed totrigger an event to start the handover measurements for the HNB in casethere is no other neighbor macro cell with good quality available. Forexample, it may be decided that handovers from UMTS macro cells to LTEHNBs may occur faster than handovers from LTE macro cells to UMTS HNBs.

In order for the WTRU to build its fingerprint information list forother RAT HNBs in Idle mode, the WTRU needs to be aware of the PCI/PSCsplit for CSG cells of other RATs. For example, the UMTS PSC split maybe broadcast in the LTE system information while the LTE PCI split maybe broadcast in the UMTS system information. The LTE SIB4 may beenhanced with a new IE umts-csg-PSC-Range while the UMTS SIB11 bis maybe enhanced with a new IE “LTE CSG PCI Split information”. Thisinter-RAT HNB split information may also be added in other existing SIBsor in new SIBs. This allows the WTRU, during an autonomous search or amanual search, to recognize which detected PSC/PCI belongs to other RATsCSG cells. When storing the fingerprint information, the WTRU may alsostore the type of RAT of the CSG cell (e.g., LTE or UMTS) so that oncethe WTRU is in connected mode; the WTRU may apply the rules defined forinter-RAT inbound mobility as described herein. Alternatively, thePSC/PCI splits for the other technology may be sent to the WTRU viadedicated RRC signaling, (e.g., measurement control). The network mayprovide the PSC/PCI split for the other RAT periodically, or thereporting may be started by one or a combination of the followingtriggers including: 1) the macro serving cell measurements reported bythe WTRU to the network to show that the macro serving cell quality isdeteriorating (e.g., is below a certain threshold); 2) the user activityis increasing leading to a demand of higher data rates; and 3) thenetwork detects that the WTRU is in a neighborhood where only HNBs of adifferent RAT than the macro serving cell are available or just a fewHNBs of the same RAT than the current macro serving cell are available.

Although features and elements are described above in particularcombinations, each feature or element can be used alone without theother features and elements or in various combinations with or withoutother features and elements. The methods or flow charts provided hereinmay be implemented in a computer program, software, or firmwareincorporated in a computer-readable storage medium for execution by ageneral purpose computer or a processor. Examples of computer-readablestorage mediums include a read only memory (ROM), a random access memory(RAM), a register, cache memory, semiconductor memory devices, magneticmedia such as internal hard disks and removable disks, magneto-opticalmedia, and optical media such as CD-ROM disks, and digital versatiledisks (DVDs).

Suitable processors include, by way of example, a general purposeprocessor, a special purpose processor, a conventional processor, adigital signal processor (DSP), a plurality of microprocessors, one ormore microprocessors in association with a DSP core, a controller, amicrocontroller, Application Specific Integrated Circuits (ASICs), FieldProgrammable Gate Arrays (FPGAs) circuits, any other type of integratedcircuit (IC), and/or a state machine.

A processor in association with software may be used to implement aradio frequency transceiver for use in a wireless transmit receive unit(WTRU), user equipment (UE), terminal, base station, radio networkcontroller (RNC), or any host computer. The WTRU may be used inconjunction with modules, implemented in hardware and/or software, suchas a camera, a video camera module, a videophone, a speakerphone, avibration device, a speaker, a microphone, a television transceiver, ahands free headset, a keyboard, a Bluetooth® module, a frequencymodulated (FM) radio unit, a liquid crystal display (LCD) display unit,an organic light-emitting diode (OLED) display unit, a digital musicplayer, a media player, a video game player module, an Internet browser,and/or any wireless local area network (WLAN) or Ultra Wide Band (UWB)module.

What is claimed is:
 1. A method of detecting a home Node-B or home(evolved) Node-B (HNB) implemented in a wireless transmit/receive unit(WTRU), comprising: detecting, based on fingerprint information, thatthe WTRU has entered into a vicinity of a HNB cell whose closedsubscriber group (CSG) ID is in a whitelist of the WTRU; sending anindication to a network entity that the WTRU has entered into thevicinity of the HNB cell, wherein the indication includes a frequency ofthe HNB cell and a Radio Access Technology (RAT) of the HNB cell;receiving a measurement configuration message; and performing themeasurements.
 2. The method of claim 1, wherein the indication is sentto the network entity via one of a new measurement type in a measurementreport message or as a new radio resource control (RRC) message.
 3. Themethod of claim 1, wherein the measurement configuration message is usedto detect one of a primary scrambling code (PSC) or a physical cellidentity (PCI) of the HNB cell on the frequency and the RAT.
 4. Themethod of claim 3, wherein the WTRU is configured with one of acompressed mode or measurement gap to measure the frequency or the RAT.5. The method of claim 1, wherein the measurement configuration messageis one of an intra-frequency measurement, inter-frequency measurement orinter-RAT measurement.
 6. The method of claim 1, wherein the indicationincludes a cell identity of the HNB cell that triggered the indication.7. The method of claim 1, further comprising signaling support of HNBcell detection on the frequency and the RAT.
 8. The method of claim 1,further comprising receiving a configuration for the RAT, wherein theconfiguration enables proximity detection and sending/receiving ofreports in response to proximity detections on a condition that the WTRUenters or exits the proximity of the HNB cell.
 9. The method of claim 8,wherein the configuration is provided in a form of a new measurementtype.
 10. The method of claim 8, wherein the configuration is providedin a radio resource control (RRC) message.
 11. The method of claim 8,wherein the WTRU starts using the fingerprint information to detectproximity of the HNB cell on the configured RAT.
 12. The method of claim1, further comprising detecting that the WTRU is exiting the vicinity ofthe HNB cell whose CSG ID is in the whitelist of the WTRU and notifyingthe network entity.
 13. The method of claim 12, further comprisingreceiving a configuration removing a measurement configuration.
 14. Themethod of claim 12, wherein a notification is transmitted via one of ameasurement report message or a new radio resource control (RRC)message.
 15. The method of claim 14, where the measurement reportmessage and the new RRC message is also used for sending the indicationto the network entity.
 16. The method of claim 1, wherein the WTRU isnot allowed to send the indication more than a certain number of timesduring a certain period of time.
 17. A wireless transmit/receive unit(WTRU) for detecting a home Node-B or home (evolved) Node-B (HNB),comprising: a processor; a receiver in communication with the processor;the processor and receiver configured to detect, based on fingerprintinformation, that the WTRU has entered into a vicinity of a HNB cellwhose closed subscriber group (CSG) ID is in a whitelist of the WTRU; atransmitter in communication with the processor; the transmitterconfigured to send an indication to a network entity that the WTRU hasentered into the vicinity of the HNB cell, wherein the indicationincludes a frequency of the HNB cell and a Radio Access Technology (RAT)of the HNB cell; the receiver configured to receive a measurementconfiguration message; and the processor configured to perform themeasurements.
 18. The WTRU of claim 17, wherein the indication is sentto the network entity via one of a new measurement type in a measurementreport message or as a new radio resource control (RRC) message.
 19. TheWTRU of claim 17, wherein the receiver is configured to receive aconfiguration for the (RAT), wherein the configuration enables proximitydetection and sending/receiving of reports in response to proximitydetections on a condition that the WTRU enters or exits the proximity ofthe HNB cell.
 20. The WTRU of claim 17, the receiver and processorconfigured to detect that the WTRU is exiting the vicinity of the HNBcell whose CSG ID is in the whitelist of the WTRU and to notify thenetwork entity.
 21. The WTRU of claim 17, wherein the measurementconfiguration message is used to detect one of a primary scrambling code(PSC) or a physical cell identity (PCI) of the HNB cell on the frequencyand the RAT.
 22. The WTRU of claim 21, wherein the WTRU is configuredwith one of a compressed mode or measurement gap to measure thefrequency or the RAT.
 23. The WTRU of claim 17, wherein the measurementconfiguration message is one of an intra-frequency measurement,inter-frequency measurement or inter-RAT measurement.
 24. The WTRU ofclaim 17, wherein the indication includes a cell identity of the HNBcell that triggered the indication.
 25. The WTRU of claim 17, whereinthe transmitter is further configured to signal support of HNB celldetection on the frequency and the RAT.
 26. The WTRU of claim 19,wherein the configuration is provided in a form of a new measurementtype.
 27. The WTRU of claim 19, wherein the configuration is provided ina radio resource control (RRC) message.
 28. The WTRU of claim 19,wherein the processor and receiver are further configured to start usingthe fingerprint information to detect proximity of the HNB cell on theconfigured RAT.
 29. The WTRU of claim 20, wherein the receiver isfurther configured to receive a configuration removing a measurementconfiguration.
 30. The WTRU of claim 20, wherein the transmitter isfurther configured to transmit a notification via one of a measurementreport message or a new radio resource control (RRC) message.
 31. TheWTRU of claim 30, where the measurement report message and the new RRCmessage is also used for sending the indication to the network entity.32. The WTRU of claim 17, wherein the processor and transmitter arefurther configured to send the indication no more than a certain numberof times during a certain period of time.